Drug cocktail touted by Trump to treat coronavirus increases chance of death by 27%, study shows

But the researchers hope their meta-analysis, which incorporated data from more than 33,600 patients, will put any questions hydoxychloroquine’s efficacy to rest.

“There is already a great number of studies that have evaluated hydroxychloroquine alone or in combination and it seems unlikely at this stage that any efficacy will ever emerge” wrote the study's authors in the journal Clinical Microbiology and Infection. “Our results suggest that there is no need for further studies evaluating these molecules”.

The researchers,, including Thibault Fiolet of Paris's Centre for Research in Epidemiology and Population Health, assessed 29 studies - processing the data of 11,932 patients who were treated with hydroxychloroquine, 8,081 who received hydroxychloroquine with azithromycin, and 12,930 in a control group that received neither.

Despite claims made by world leaders , the authors said the analysis “shows that hydroxychloroquine alone is not effective for the treatment of Covid-19 patients and that the combination of hydroxychloroquine and azithromycin increases the risk of mortality".